Micro-fluid ejection heads are useful for ejecting a variety of fluids including inks, cooling fluids, pharmaceuticals, lubricants and the like. A widely used micro-fluid ejection head is in an ink jet printer. As the fluid droplet size decreases and speed of fluid ejection increases, factors that effect fluid ejection are magnified requiring solutions to problems that previously did not exist or were too insignificant to be noticed.
Micro-fluid ejection heads may be stationary or, as in the case of many ink jet printers, may advance across a receiving medium in a fluid ejection swath. In order to provide accurate placement of fluid droplets on the medium during movement of the ejection head across a medium, a staggered array of fluid ejectors in a substantially linear array of fluid ejectors may be used. Typically, at least sixteen different distances from a fluid supply slot are used to provide the staggered array of fluid ejectors.
In addition to the staggered array, fluidic interactions between adjacent fluid ejectors may require a staggered firing sequence for the ejectors. Hence, in order to provide a substantially linear placement of fluid droplets on the receiving medium, the firing sequence, the ejector location, and fluidic interactions must be considered. As the speed of droplet ejection increases, there is a need to improve the design and operation of micro-fluid ejection heads to provide rapid firing of ejectors with reduced fluidic interactions and without sacrificing droplet placement accuracies.
In view of the foregoing, exemplary embodiments of the disclosure provide an improved fluid ejector placement pattern and firing sequence that may significantly reduce inaccuracies in droplet placement on a fluid receiving medium as an ejection head travels in an ejection swath across the medium.
In an exemplary embodiment of the disclosure there is provided a micro-fluid ejection head and method for reducing a stagger pattern distance and improving droplet placement on a receiving medium. The micro-fluid ejection head includes a substrate containing a plurality of ejection actuators on a device surface thereof and a fluid supply slot for providing fluid to be ejected by the micro-fluid ejection head. The ejection head also includes a flow feature component in flow communication with the fluid supply slot and configured for providing fluid ejection chambers and fluid supply channels for the fluid ejection chambers. Adjacent first and second ejection actuators in a substantially linear array of ejection actuators are each spaced a first distance from the fluid supply slot and second and third ejection actuators in the linear array of ejection actuators are each spaced a second distance from the fluid supply slot that is less than the first distance.
In another exemplary embodiment of the disclosure there is provided a method for reducing inaccuracies in droplet placement on a fluid receiving medium as an ejection head travels in an ejection swath across the medium. The method includes firing a first ejection actuator in a first firing step, wherein the first ejection actuator is disposed in an adjacent first pair of ejection actuators in a substantially linear column of ejection actuators that are each spaced a first distance from a fluid supply slot. A second ejection actuator is fired in a second firing step, wherein the second ejection actuator is disposed in an adjacent second pair of ejection actuators in the substantially linear column of ejection actuators that are each spaced a second distance from the fluid supply slot. The second ejection, actuator and the first ejection actuator are spaced apart orthogonal to the fluid supply slot by at least a third pair of ejection actuators between the first pair and second pair of ejection actuators in the substantially linear column of ejection actuators.
Yet another exemplary embodiment of the disclosure provides a method for reducing a fluid ejector stagger distance from a fluid supply slot in a substantially linear array of ejection actuators in a micro-fluid ejection head while ejecting fluid droplets onto a receiving medium as the ejection head travels in an ejection swath across the receiving medium. The method includes disposing the ejection actuators in adjacent pairs of ejection actuators to provide pairs of ejection actuators disposed no more than twelve different distances from the fluid supply slot. A first ejection actuator in a first pair of ejection actuators is activated to provide a first fluid droplet on the receiving medium. A second ejection actuator in second pair of ejection actuators is then activated to provide a second fluid droplet on the receiving medium that is substantially aligned with the first fluid droplet. The second pair of ejection actuators is spaced apart from the first pair of ejection actuators along the substantially linear array by at least a third pair of ejection actuators.
An advantage of the exemplary embodiments of the disclosure is that a total stagger distance from a fluid supply slot may be reduced while still providing substantially accurate droplet placement on a fluid receiving medium. Another advantage of the disclosed embodiments is that fluidic interactions between adjacent ejectors may be minimized thereby decreasing the delay time required between firings of adjacent fluid ejectors.